Power-Sonic Sealed Lead Acid Batteries - Technical Manual - Manual (Page 12)

0
Performance Data
Shelf Life & Storage
Low internal resistance and special alloys in the electrodes assure a low self discharge rate and, consequently, a long
shelf life. If kept at 20°C (68°F), about 60-70% of the nominal capacity remains after one year of storage. Due to the
self-discharge characteristics of this type of battery, it is imperative that they be charged within 6 months of storage,
otherwise permanent loss of capacity might occur as a result of sulfation.
The rate of self discharge varies with the ambient temperature. At room temperature (20°C (68°F)) it is about 3% per
month. At low temperatures it is nearly negligible; at higher ambient temperatures self discharge increases.
To obtain maximum battery life and performance, batteries should be recharged as soon as possible after each use and
not stored in a discharged state. If possible batteries should be stored at 20°C (68°F) or lower, and recharged every six
months when not in use.
Battery Life
Cyclic Use: The number of charge/discharge cycles depends on the capacity taken from the battery (a function of
discharge rate and depth of discharge), operating temperature and the charging method.
Figure 8: Self Discharge Characteristics
Figure : Relationship between depth of discharge and number of cycles
as well as increases of capacity during the early cycles.
Capacity R
etention Ratio(%)
Storage Period (Months)
R
etention Capacity (%)
Number of Cycles